Memory
Weeks 1 and 2
The story
so far…
ENCODING
Evidence?
DURATION
Evidence?
CAPACITY
Evidence?
Sensory
Memory
By Sensory
modality.
• S.T.M.
• L.T.M
Acoustically
Semantically
(sometimes visual)
SPERLING
BADDELEY
BADDELEY
½ - 2 secs
18 – 30 sec
Life time?
SPERLING
Very
limited
SPERLING
PETERSON & PETERSON
7 + or - 2
Infinite?
MILLER
Encoding / Storage / Retrieval
Cognitive Approach
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Memory: the storage and retrieval of information
Computer analogy – human memory is like a computer; it
allows us to process and store information for later use
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Encoding (transform the info so it can be stored – visual, acoustic,
semantic)
Storage (holding onto the information)
Retrieval (bringing the memory out of storage)
One of the most widely accepted theories of memory is the
Stage Model of Information Processing
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the model proposes that information is processed and stored in 3
stages
information is stored in multiple locations throughout the brain in
the form of networks of connections
Stage theory of Memory
(cognitive approach)
 Multi-Store
Model
 Atkinson and Shiffrin (1968)
!
Remembering . . .
 For
us to remember a piece of info well,
we need to:
Pay attention to it
 This gets it from the SM to the STM
 Rehearse it
 Maintenance rehearsal keeps it in our STM
 Elaborative rehearsal can get it to our LTM
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Multi-store Model
Atkinson and Shiffrin (1968)
Echoic Store
Iconic Store
Evidence?
As a group discuss the evidence to support
this model
 Find at least one piece of evidence for each
store – all the answers are in your memory
booklet, page 4
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Use other texts to expand your knowledge of
these studies
SM :
•set of limited capacity, modalityspecific stores (eg vision, sound)
•Duration: BRIEF period (1-2 s).
•Info is unprocessed.
•Info is passively registered – i.e.
we cant really control what enters
Echoic Store
Multi-store Model
Atkinson and Shiffrin (1968)
Iconic Store
STM :
•Capacity: limited (about 7)
•Duration: Very limited (18secs)
•Encoding: acoustic (sound)
LTM
•Capacity: unlimited
•Duration: unlimited (lifetime)
•Encoding: semantic (meaning)
Further research that supports the MSM
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Experiment by Sperling (1960):
– Presented a grid of letters (3 rows ) for 50ms
– People recalled average: 4 letters but were aware there were more.
– That was called whole report technique
– Sperling then used “partial report” technique…
– Showed chart for 50 ms then AFTER played 1 of 3 tones
– High tone = they had to recall top row
– Medium tone = they had to recall middle row
– Low tone= had to recall bottom row.
– They could recall average of 3 letters from the correct row.
– …showed that iconic memory held up to 9-10 items!
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Duration:
– Info decays within about 2 secs (or less)
Further evidence for distinction between
STM & LTM
Funny
Serial Position
Effect: Test
Careless
Hospital
Beef
Mug
Aspect
Business
Check
Models
Percentage
Life
Television
Job
Elbow
Water
Primacy
Recency
Condition 1: found the
expected serial position curve.
Condition 2:
•found the distracter task had
disrupted the recency effect – so
the last few words were displaced
from the STM & not well recalled.
•The first few words were NOT
affected as they had been
rehearsed & so had passed into
the LTM.
• EVIDENCE that the STM &
LTM are separate stores..
• EVIDENCE that rehearsal
pushes info from STM to LTM
Individual Activity – no notes please
• On a piece of A4 paper, draw the model
• Add the names of research that provide evidence of
each stage
Evaluation
the Model
• Below, bullet point
2 strengths &of
2 limitations
of the
model
Multi-Store Model (stage model)
Strengths
• Useful in memory research – provides the foundations for future
research
• Good supporting evidence: SM (Sperling 1960); STM (Miller
1956, Peterson&Peterson 1959, Baddeley 1966); LTM (Bahrick
1974, Baddeley)
• Primacy & Recency effect shows separate stores (Glanzer &
Cunitz, 1966)
• Korsakoff’s Syndrome (amnesia due to chorionic alcoholism).
People with this can recall last items on a list (suggesting
unimpaired STM) but struggle with first items (suggesting LTM is
poor)
MSM Weaknesses
REHEARSAL is central to MSM but there is lots of evidence to suggest that
this is the worst way to pass on info…meaning is the best way to learn
• Kulik & Brown: “flashbulb memory” where highly emotional, shocking
events (eg.9/11) go into LTM with NO rehearsal.
Atkinson & Shriffin thought info flows from STM to LTM (one way!) & has to be
processed by STM before getting to LTM.
BUT in order to identify letters “B,D,G “ etc – you need to get stored
information from LTM that B makes the sound “bee” = not 1-way
MSM suggests 1 LTM store, but evidence from amnesia patients indicates
different LTM stores
• Tulving 1972 identified 3 stores
• Semantic (knowledge of world/words) Episodic (what you did
yesterday/last week) Procedural (doing things e.g play music)
Types of Long Term Memory
Procedural
Semantic
Episodic
Our “how to” memory, e.g: riding a bicycle
we may not be able to explain it in words
or even know that we have this memory.
Little research has been done on this.
Our “know that” memory, e.g: capital of
France because it is processed by
meaning it is organised in the way it was
originally learnt. Most memory research
has looked at this.
Our “episodes of life” or autobiographical
memory, e.g: last holiday, 18th birthday.
Includes Flashbulb Memories which are
vivid, emotive memories – ( eg 9/11 ).
Working Memory Model
(cognitive approach)
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Another model that illustrates the cognitive approach is
Working Memory Model by Baddelely & Hitch 1974
The model looks at the functional components of cognition
that allow humans to comprehend their immediate
environment
It also proposes how humans retain information about their
past experience, which can then support the learning of new
knowledge, problem solving and achieving goals
Agreed with MSM (stage model) that A & S proposed but felt
that a single STM store wasn’t sufficient
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One STM store couldn’t account for everything that memory could
do
B & H thought that STM must have more than one component
Working Memory Model
How did they test it?
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Baddeley & Hitch asked ‘what is STM for?’
Experiment time!!!
Lets try it - groups of 4 please
2 participants & 2 experimenters
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Participants leave the room please
Experimenters: 1 timer/recorder; 1 reader
This procedure must be carried out in a quiet space – use
canteen, corridor, photocopy area, stairwell ….
How did they test it?
They devised the ‘dual task technique’.
 Participants were asked to perform a
reasoning task and at the same time recite
aloud a list of six digits or repeatedly saying
‘the the the’.
 Performance was then compared to when
the reasoning task was done on its own.
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What did they find?
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The speed of answering the true/false to the verbal
reasoning task was slower when having to do another
task (e.g. say ‘the the the’ repeatedly) than when just
focusing on the task alone.
Average time taken
to solve verbal
rehearsal
Control group
2.79
‘the, the, the’
3.13
‘1, 2, 3’
3.22
Random six-digit
number
4.27
Conclusion:
The STM must have more than one
component and must be involved in
processes other than simple storage
e.g. reasoning, understanding and
learning, perception
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Clearly a cognitive approach underpins this model!
What is working memory?
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Focuses on STM and sees STM as much more active than
SM and LTM.
It is what we are using all the time when we are thinking
about things and trying to learn new information
The information may come in two sources e.g. new sensory
info and existing info stored in LTM
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For example, if you were drilling a hole using a power drill, you would
use new sensory information to place the drill over the area you
wished to drill the hole and existing information about how to use the
drill
You can illustrate
working memory by
asking how many
windows in your house?
3 main components to STM:
•
Central Executive (the supervisor)
•
The phonological loop (the inner voice)
•
Visuo-spatial sketchpad (the inner eye)
Working Memory Model
Baddeley & Hitch
1974
The CENTRAL EXECUTIVE controls
working memory by focusing attention
on one or more of sub-systems and
determines flow into LTM.
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Limited capacity
Can process information from any sense (visual, auditory,
smell, taste etc)
It works like a control mechanism and has responsibility for:
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Central
Executive
Switch attention
Divide attention
Link to LTM
Like a conductor
instructing an
orchestra
It is supported by two slave systems, which can be used as
storage systems to free up some of its own capacity to deal
with more demanding tasks.
The slave systems have separate responsibilities and work
independently of one another.
http://www.youtube.com/watch?v=aseitqCZKQo
Dual Task Results
Involvement of
central executive
Average
time taken
to solve
verbal
rehearsal
Control group
None
2.79
‘the, the, the’
Very little
3.13
‘1, 2, 3’
Some
3.22
Random six-digit
number
The most
4.27
Articulatory Phonological Loop
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The ARTICULATORY PROCESS
encodes acoustically and uses
REHEARSAL to process information.
and the PHONOLOGICAL STORE
which also has a limited capacity.
Limited capacity
The ‘inner voice’
Temporary storage system which stores material in a
verbal form and allows you to rehearse verbally
‘articulatory loop’
Words get maintained by repeating it in your head
The loop allows for the rehearsal to happen.
Offers the explanation of how capacity of STM is 7+/2 items (Miller 1956) and the duration of STM is
approx. 18 seconds unless rehearsal takes place
(Peterson & Peterson, 1959)
The visuo-spatial sketchpad
The VISUO-SPATIAL SKETCHPAD
encodes and stores visually,
limited in capacity and duration.
Limited capacity
 The ‘inner eye’
 Temporary memory system for holding
visual and/or spatial information (e.g.
people’s faces).
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Evidence for the WMM
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Word Length Effect – Baddelely (1975)
Try it!
The phonological loop holds the amount of info
that you can say in 2 seconds
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This makes it hard remember a list of long words e.g.
association
The phonological loop can rehearse the shorter
words quicker
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therefore, more of list one can be stored and recalled and
than list two
List 1
List 2
Coin, door, man, six, tap
Encyclopaedia, monotonous,
disastrous, euphonium,
subsequently
Evidence for the WMM
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Dual Task technique experiment (1976) (that we
did earlier… ‘the, the, the’)
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Explains why it’s easier to do two different tasks at
the same time than two similar ones
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watching TV and listening to someone
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is easier than
Uses different slave systems: Phonological loop &
Visuo-spatial sketchpad
talking to someone while listening to information (e.g.
through an ear piece)
Uses same slave systems: Phonological loop &
Phonological loop
The Introduction of the Episodic Buffer
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http://www.youtube.com/watch?v=3a_cF46UiEU
In 2000 Baddeley added the episodic buffer
The episodic buffer acts as a 'backup' store which
communicates with both long term memory and the
This can be thought of
components of working memory.
as a computer trying to
download something
…streaming data
Evaluating Working Memory
Find 2 strengths & 2 limitations Model
+ The working memory applies to real life tasks:
- reading (phonological loop)
- problem solving (central executive)
- navigation (visual and spatial processing)
+ Evidence from Baddeley & Hitch (1976) shows that we can
process more than one task using STM.
+ Evidence for phonological loop: word length effect
+ Helps to explain multi-tasking & learning difficulties
- Does not explain how central executive works
- The capacity of the central executive has never been measured
- WMM is primarily a model of STM so not a comprehensive
model
Next week
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Biological Approach to Memory